Shot-blasting machine

Abstract

A loader arrangement 7 of a shot-blasting machine includes a bucket loader 29 having a tip opening that can be opened and closed by means of a lid 35 . The loader arrangement 7 also includes a swivel arm 32 , which is vertically and pivotally attached to a frame 4 via a linkage 31 , for vertically swiveling the bucket loader 29 , and a chain block 34 for swiveling the arm 32 . Once the bucket loader 29 has reached the upper position above a rotary drum 5 by means of the swivel arm 32 , a guide means 30 , which is attached to the arm 32 , allows the bucket loader 29 to approach the drum 5 through its top opening by driving a hydraulic cylinder 33 , while the tip of the bucket loader 29 is opposed to the bottom wall of the drum 5 . Once the tip of the bucket loader 29 is close to the bottom wall or the inner peripheral wall of the drum 5 , the lid 35 is opened to drop the work pieces in the bucket loader 29 into the drum 5 . Because the work pieces thus tumble from the low level relative to the bottom wall or the inner peripheral wall of the drum 5 , the impact of the work pieces being dropped can be inhibited, and thus damage to the work pieces and the noise of the sounds of hitting can be reduced.

1. A shot-blasting machine for cleaning work pieces, comprising:
 a frame; 
 a cylindrical drum inclinably mounted on said frame such that said drum is rotated about the longitudinal axis thereof, said drum having a top opening, an opposite bottom wall, and an inner peripheral wall so as to define a chamber in which the work pieces are processed therebetween; 
 a flapper for opening and closing said top opening of said drum; 
 a device mounted on the inner surface of said flapper for impelling abrasive particles into said chamber; 
 a bucket loader having an opening leading-end and closing leading-end and defining a loading chamber in which the work pieces are loaded; 
 adjusting means for adjusting the degree of the opening of said leading end of said bucket loader; 
 transferring means for reciprocatingly transferring said bucket loader in a path that includes a lower position in which the work pieces are loaded into said loading chamber of said bucket loader through said opened leading end, an intermittent step in which said bucket loader is upwardly moved when the leading end is closed, and an upper position in which said closed leading end of said bucket loader is opposed to said opened top opening of said drum; 
 guide means for guiding said bucket loader when it reaches said upper position such that said bucket loader advances to and withdraws from said processing chamber of said drum through said top opening thereof with said leading end of said bucket loader being opposed to said bottom wall of said drum; and 
 wherein said adjusting means opens said leading end of said inserted bucket loader in said processing chamber of said drum after said leading end accesses said bottom wall or said inner peripheral wall of said processing chamber, whereby said loaded work pieces in said bucket loader fall into said processing chamber of said drum. 
 
   
   
     2. The shot-blasting machine of  claim 1 , wherein said guiding mechanism includes a hydraulic cylinder or an electrical cylinder with a servomotor. 
   
   
     3. The shot-blasting machine of  claim 1 , wherein said adjusting means includes a lid for closing and opening said leading end of said bucket loader by means of a hydraulic cylinder or an electrical cylinder with a servomotor. 
   
   
     4. The shot-blasting machine of  claim 1 , further including a cabinet inclinably mounted on said frame, said cabinet having a superior edge defining a top entrance, and wherein said rotatable drum is rotatably mounted within said cabinet such that said drum and said cabinet are inclined in unison with said top opening of said drum and such that said top entrances of said cabinet are aligned. 
   
   
     5. The shot-blasting machine of  claim 4 , wherein said flapper has an inner edge, and wherein said flapper closes both said top opening of said drum and said top entrances of said cabinet and in the closed position of said flapper. 
   
   
     6. The shot-blasting machine of  claim 5 , further including a labyrinthine structure for closing a gap between said superior edge of said cabinet and said inner edge of said flapper and a gap between said top opening of said drum and said inner surface of said flapper when said flapper is in the closed position, and an elastic sealing compound fitted along said inner edge of said flapper to close a gap between said labyrinthine structure and said inner edge of said flapper. 
   
   
     7. The shot-blasting machine of  claim 6 , wherein said labyrinthine structure includes:
 a compressing member extending from the inner surface of said superior edge of said cabinet to said elastic sealing member for compressing said elastic sealing compound to close a gap between said superior edge of said cabinet and said elastic sealing member when said flapper is in the closed position; 
 a flange member extending from the inner surface of said compressing member to a position close to the outer peripheral wall of said drum; 
 a planner member mounted on the inner surface of said flapper for closing a gap between the inner surface of said flapper and said top opening of said drum around said impelling device, wherein the outer edge portion of said planner member is opposed to said flange member; and 
 a cylindrical member extending from the inner surface of said planner member near the outer edge thereof to the upper surface of said flange member. 
 
   
   
     8. The shot-blasting machine of  claim 7 , wherein the distance of the gap between the leading edge of said cylindrical member and the upper surface of said flange member is three to five times the maximum diameter of said abrasive particles. 
   
   
     9. The shot-blasting machine of  claim 8 , wherein the proximal portion of said flange member is provided with a plurality of apertures such that said abrasive particles that have migrated into the clearance between the proximal portion of said flange member and said elastic sealing compound are returned into said cabinet. 
   
   
     10. The shot-blasting machine of  claim 7 , wherein said compressing member compresses said elastic sealing compound to 5 to 80% of the initial size of it when said flapper is in the closed position.